14hp Power Soultions low on power?

[Cowboy Billy]

   I have a 14-1 power solutions listeroid with a ST-12 generator. I got it in 2006 and only have about 20 hrs on it. When I lost power at home it had no problem running the whole house, window air conditioner and  6.5 hp 60 gal campbell housfield  air compressor.

   But I took it to the farm to run a 15" planner 3 hp and a dust collector 1hp. And it just cannot maintain voltage. I start the planner and the engine luges right down Dropping from 240 volts to 210. And while it was planing cedar it was lugging down to 220v. And when I put in a 7" wide spruce board in the planner Dropping from 1000 rpm to around 700 until I could hit the stop switch. While it was smoking a little it was not rolling black smoke out the exhaust.

   If I figured it right 14hp is 9800 watt so I figured real world out put should be 8000 to 9000 watts 0r 35 to 40 amps 220. But it did not trip the 20 amp breaker on the pannel. I don't think I am expecting too much by running 4hp of electric motors off a 14 hp engine. Or does a 14hp single cylinder just not have enough power strokes a minute to keep up.

   This engine is entirely stock other than replacing the fuel lines which decomposed and I replaced. I don't know if the injector timing may be off, bad spring on the govener, Injector rack not opening enough or something else entirely.

   I really hope this engine is enough to do the job and you all can help me get it up to snuff. While I do have a 20hp changfa I can put on it I would much rather keep the lister and have it do what I need it to.

Sorry about the blurry picture all I had was a cheep cell phone camera.



But I am glad it was able to get my cedar planned and I was able to get my new front porch built on my bunkhouse.



Billy


   

[dieselgman]

The symptoms sound like you are overloading that engine. General rule of thumb for a 14hp engine will be 7kW continuous output with a belt drive system and everything else working properly. The start-up surge on your planer may be a bit much for your setup... presumably a 3-phase motor? Sounds odd that it can handle the 6.5 hp compressor though. Do you have some kind of current (Amps) instrumentation on your setup? That would be instructive to know what the loads are actually seen at the set. Inductive loads pose some challenges for any generator system and your actual power factor may be fairly low. I would suggest calibrating the set with known loads (and proper instruments) until you find its sweet spot for maximum output, then work the numbers to determine its actual horsepower delivery. (also known as load-testing).

dieselgman

[dieselgman]

You can use a combination of small resistive heaters (1500watts each) to do this... but be sure to load all phases evenly.

dieselgman

[Billyrob]

I believe this is the answer to your problem.

First, let’s look at your system.    The weakest point is the diesel motor at 14 HP.

This will give you 10.5 KW regardless of the generator being rated at 12 KW.
That will be 45 Amps at 230 Volts.

Generator sizing becomes more difficult when electric motors are involved, due to their large starting demand.   Typically a motor can require 3 to 6 times running watts to start.
The generator must be able to supply the large initial power requirements of starting the motor.
This is also assuming the voltage does not dip more than 25%.

Sizing a generator for single phase motor starting LRA (Locked Rotor Amps) (motor at standstill):

The formula is:

Motor HP x KVA per HP x (1000 / Motor Voltage) = LRA (Locked Rotor Amps).

Your Example:   A 3 HP, Code J motor connected to 230 Volts, requires what LRA?

Typically a 3 HP motor will be 8 KVA per horsepower

The formula becomes:

3 x 8 x (1000/230) =  24 X 4.35  = 104.3 LRA.

The generator must produce 104.3 Amps at 230 Volts, to safely start this motor.

Multiply 104 amps x 230 Volts = 24,000 Watts or 24 KW generator size.

Since your set up with the 14 HP motor will give you 10.5 KW,  I am not surprised you have difficulty starting and running this motor.


Best regards !!!!

Bill

[dieselgman]

Well, I suppose that the ST designation on the generator head confirms we are strictly talking single phase power and motors here, but wasn't it stated that the set will start and run the 6.5 hp air compressor properly? If this is correct information then why would a 3hp motor cause an overload... perhaps the air compressor has a much more efficient motor with drastically less startup load?

Thanks for your proper engineering approach Bill! This is certainly a strength and benefit of a forum discussion!

dieselgman

[Cowboy Billy]

Thanks Dieselgman

    Yes it is a single phase motor. As for the air compressor it was a campbell hausfield I got a TSC that had "claimed" 6.5hp 10 years ago.  That was back when the big stink came out that manufactures were advertising theoretical hp ratings not the real hp. And what ever brief start up surge load must have been handled out of the stored mechanical energy in the flywheels.

Thanks Bill

    I had no idea that it required that kind of start up load. And considering the cutter head weighs at least 10lbs and spins up to 5000rpm it has a long start up time too. I know the dust collector pulls 4.5 amps at 230v. I don't have the running amps on the 3hp but everything I looked up was 13.5 to 18 amps and I was figuring 15. But obviously its pulling more than that under load.

    Well at least I know now its not just a matter of tuning up the lister and I'll bring it back home and use it as a back up generator as it works just fine for that. But it also appears my direct drive 20hp chingfa is not going to work either so I don't know what I am going to power the planner with unless I rig up a pto drive off of a tractor.

Billy

[Billyrob]

Hi Guys,

Horepower ratings on air compressors is an industry SCAM to get you to buy the one with the bigger (FAKE) horepower rating......

From the internet...........

Sure, there's a big sticker on the tank, with a big "6 HP" on it. But if you look at the nameplate on the motor itself, the place where the horsepower is supposed to be listed, it is either blank, or says "SPL". (Someone's Probably Lying?) A closer look at the big sticker on the tank may even reveal some fine print saying "peak" horsepower.

We're talking about portable electric compressors here, that run off of an ordinary household outlet, 120 volts.

This is one case that I've reported to several "consumer protection" type agencies over the past years. Knowing what I do about electrical and mechanical things, I immediately had to take a second look when I saw these compressors on the floor at a local home center. The motor on it was physically way to small to be anywhere near 5 real horsepower, but the store's poster advertised it as "5 hp".

I made note of the electrical ratings on the motor, When I got home I ran the numbers, and taking into acount the efficiency and power factor of the motor, I concluded it was actually a 1-3/4 hp. unit, 2 hp. max.

So what's happening here is an outright lie. And it's several different manufacturers doing it. The air compressor manufacturer does not make the electric motor, but buys it from a motor manufacturer. The motor manufacturer knows it could get in trouble by putting a false horsepower rating on the motor, because there are standards for determining horsepower. If someone were to take that motor off of the compressor and use it in another application, the truth would come out. So to stay out of trouble, they don't mark the hp. rating on the motor. And they also call it a special "air-compressor duty" motor, and say 'do not use in any other application', or something to that effect. Gee, I wonder why?

So it's the air compressor manufacturers that are twisting the truth. Obviously the motor manufacturers are aware of it, but have their butts covered.

My complaints about this fell on deaf ears, for the most part. One manufacturer sent some papers to the consumer protection agency, with charts and graphs, explaining basically that if you can make a motor put out 5 hp. long enough to get a reading, then it's a 5 hp. motor. Uh Huh. But the agency accepted that answer. I don't imagine that anyone at such an agency would know a horsepower from a watt.

The truth is, 1 horsepower is the amount of power needed to lift a weight of 33,000 pounds a distance of 1 foot in one minute, or 550 foot-pounds per second. And a motor rated at 1 (real) horsepower could do just that. Also, most electric motors are capable of producing two or three times their rated power during start-up, just for a second or two, to get up to speed. This is probably where the "peak horsepower" rating comes from, but really has no useful purpose for the consumer.

Additionally, a standard wall outlet (120 volt) can produce only 1800 to 2400 watts of electricity. (Volts X Amps = Watts.) A commonly used formula for converting watts into horsepower is 1000 watts equals 1 horsepower. This accounts for losses in the motor. So a 15 amp wall outlet can run 1800 watts or only 1.8 hp., and a heavier duty 20 amp outlet, as you might find in your kitchen, could run 2400 watts, or 2.4 hp. So any appliance that runs on regular power, and claims to be more than a couple of horsepower, is BS!

Early in the 2000's, I read that there was a class-action lawsuit about the air compressors, and the manufacturers agreed to cut the BS, but I still see them for sale every day, all the way up to 6.5 hp. now. I recently found an imported unit that is brave enough to actually list "5hp" on the motor itself, but acording to the electrical info on the motor, same crap, it's 2 hp. max.

Now you have the real story.........

Cheers !!!!

Bill

[Billyrob]

Hi Cowboy Billy,

I have a portable 3000 watt (Optomistic rating)  YANMAR diesel generator I made up from pieces picked up at aution sales and ebay.

Home made panels, etc...........











This set up will NOT START my table saw with a 3/4 horsepower motor for the same reasons as above.

High torgue items may be even worse to start.  


Best regards,


Bill

[overbore]

Since it wont start your saw, you will send that sweet unit to me---Right?? Don't I wish.

Well done, Sir.
 overbore

[Cowboy Billy]

Thanks again for all the help Bill

   I have to say I am shocked at the difference in engine hp and motor hp. And how much power a electric motor requires to develop its power. I'm kicking myself for not buying big pto generator I saw at a auction two years ago. I remember thinking I would never need that much power and it would be silly to put hrs on a tractor just to make power.

Billy

[dieselgman]

There is of course a wide range of motor ratings and efficiencies that have varying start-up demands. We run (and start) a 25hp electric fire pump motor with a 60kW genset and about 90hp. That has proven to be well within the rating of the genset and never loads up the set excessively on startup. This one runs at startup closer to 3.5KVA per horsepower I believe, and includes a good buffer for other simultaneous loads. Of course this is 3-phase so somewhat more efficient than single phase.

We recommend folks with motor-starting requirements to go with 3-phase STC generator heads matched with the newest high-efficiency motors.

dieselgman

[SHIPCHIEF]

UP TO THE FARM?
Do you mean the farm is at a higher altitude?
Engines don't maked sea level rated power if they are operated at higher altitudes.
So add that to power factor issues and high starting current loads.
Lacking amp meters for total amps and or leg amps, and a power factor meter ($) we are just guessing.
I'm adding a turbocharger to my 25/2 for a small increase in power. I'm about half done, and might have to reassemble it if the power goes out...
On the other hand, you may have a power loss due to something simple, like a restrictive exhaust, tappets out of adjustment, dirty air filter, or poor fuel.
Running with low jacket water temp or a partially clogged injector?
Just throwing stuff at the wall, maybe something will stick.

[cujet]

I would absolutely try to get more air/fuel and improve exhaust before anything else. A stationary "emergency" diesel engine should be capable of reaching the smoke limit.

My engine has one cam lobe (the one that drives the RH injector) that is improperly timed. As such, one of my injector pumps does not achieve a full stroke and that cylinder is down on power. Easy to see and measure the differences between the cylinders.

[Cowboy Billy]

Thanks again Dieselgman

    At this point I can't afford to change over to 3 phase. But I know on a ST generator I have to energize both the rotor and stator. Does going to a PMG generator offer any significant gain in power out put to power input?

Thanks ShipChief

   In this case UP means north. The farm is 350 miles from where I live and is totally off grid. The elevation is 750' above sea level. The original fuel like broke down and turned into goo and stated leaking and started leaking. So I guess some of that could have gotten into the injector. Eventually I would like volt and amp meters. But right now I have severyl large projects going on. My Dad and Brother bought 80 acres in 2006 that adjoined Dads and My 40. The 120 acre plot was all woods and thick without any trails. I had to build a 1/4 mile of road across my Uncles just to get to it. I do 95% of the work up there but I am also planning on moving there when I get it liveable. My bull dozer is down right now and the loader and tractor need work. We also have a woodmizer sawmill and I need to get started sawing lumber to build a cabin with. But things are coming along and I am happy with the progress.

Thanks Cujet

   I agree my lister needs some work to get up to full potential. But according to Bill's figures even if it was running at 110% neither that or the gen head is up to supplying my power needs. So I am going to bring that one home. I have a 20hp chingfa and 15KV generator that I can put together. And while that will still be short of power it may be acceptable until I can find a deal on a 24KV pto generator I can put on my 65hp tractor.

Billy

   

[dieselgman]

I still recommend putting on some instrumentation before jumping into an oversized genset that might not be very efficient for you. Yes,  a PMG head is going to deliver more useable power for a given horsepower input, but the initial costs are high and serviceability may be an issue with these. I have seen a number of complaints in this regard - though not with the ones we have handled. I believe that current stock in a 6.5kW 1800rpm 60Hz head is $1250 for the PMG style.

dieselgman